1. File of the Invention
This invention is related to a semiconductor memory card which is connected with and uses an external device.
2. Description of the Related Art
The semiconductor memory card described in Japan Laid Open Patent 2007-128959 is arranged with a substrate with a first conductor pattern formed on the top surface and a second conductor pattern formed on the bottom surface and a memory package solder mounted on the circuit substrate and at least one part of the first conductor pattern and at least one part of the second conductor pattern have a symmetrical shape seen from the planar surface of the circuit substrate. In this semiconductor memory card, warping of the circuit substrate can be controlled at the time or a thermal reflow process of the semiconductor memory package.